summaryrefslogtreecommitdiff
path: root/tools/perf/util
diff options
context:
space:
mode:
authorIan Rogers <irogers@google.com>2023-12-07 04:16:53 +0300
committerArnaldo Carvalho de Melo <acme@redhat.com>2023-12-20 20:56:10 +0300
commite77b0236cd0cd1572c6a9b25097b207eab799e74 (patch)
treef5a696d86e7d54804b39f6b817559549ee1545f1 /tools/perf/util
parent9084952704ba075de28684301ec282b6626b5e7a (diff)
downloadlinux-e77b0236cd0cd1572c6a9b25097b207eab799e74.tar.xz
perf maps: Add maps__load_first()
Avoid bpf_lock_contention_read touching the internal maps data structure by adding a helper function. As access is done directly on the map in maps, hold the read lock to stop it being removed. Signed-off-by: Ian Rogers <irogers@google.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com> Cc: Changbin Du <changbin.du@huawei.com> Cc: Colin Ian King <colin.i.king@gmail.com> Cc: Dmitrii Dolgov <9erthalion6@gmail.com> Cc: German Gomez <german.gomez@arm.com> Cc: Guilherme Amadio <amadio@gentoo.org> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@arm.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: K Prateek Nayak <kprateek.nayak@amd.com> Cc: Kajol Jain <kjain@linux.ibm.com> Cc: Kan Liang <kan.liang@linux.intel.com> Cc: Leo Yan <leo.yan@linaro.org> Cc: Li Dong <lidong@vivo.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Miguel Ojeda <ojeda@kernel.org> Cc: Ming Wang <wangming01@loongson.cn> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Nick Terrell <terrelln@fb.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ravi Bangoria <ravi.bangoria@amd.com> Cc: Sandipan Das <sandipan.das@amd.com> Cc: Sean Christopherson <seanjc@google.com> Cc: Steinar H. Gunderson <sesse@google.com> Cc: Vincent Whitchurch <vincent.whitchurch@axis.com> Cc: Wenyu Liu <liuwenyu7@huawei.com> Cc: Yang Jihong <yangjihong1@huawei.com> Link: https://lore.kernel.org/r/20231207011722.1220634-20-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/util')
-rw-r--r--tools/perf/util/bpf_lock_contention.c2
-rw-r--r--tools/perf/util/maps.c13
-rw-r--r--tools/perf/util/maps.h2
3 files changed, 16 insertions, 1 deletions
diff --git a/tools/perf/util/bpf_lock_contention.c b/tools/perf/util/bpf_lock_contention.c
index f1716c089c99..31ff19afc20c 100644
--- a/tools/perf/util/bpf_lock_contention.c
+++ b/tools/perf/util/bpf_lock_contention.c
@@ -318,7 +318,7 @@ int lock_contention_read(struct lock_contention *con)
}
/* make sure it loads the kernel map */
- map__load(maps__first(machine->kmaps)->map);
+ maps__load_first(machine->kmaps);
prev_key = NULL;
while (!bpf_map_get_next_key(fd, prev_key, &key)) {
diff --git a/tools/perf/util/maps.c b/tools/perf/util/maps.c
index 986daa1b0497..024a6c9f72c4 100644
--- a/tools/perf/util/maps.c
+++ b/tools/perf/util/maps.c
@@ -793,3 +793,16 @@ out:
}
return err;
}
+
+void maps__load_first(struct maps *maps)
+{
+ struct map_rb_node *first;
+
+ down_read(maps__lock(maps));
+
+ first = maps__first(maps);
+ if (first)
+ map__load(first->map);
+
+ up_read(maps__lock(maps));
+}
diff --git a/tools/perf/util/maps.h b/tools/perf/util/maps.h
index e4a49d6ff5cf..b7ab3ec61b7c 100644
--- a/tools/perf/util/maps.h
+++ b/tools/perf/util/maps.h
@@ -142,4 +142,6 @@ void __maps__sort_by_name(struct maps *maps);
void maps__fixup_end(struct maps *maps);
+void maps__load_first(struct maps *maps);
+
#endif // __PERF_MAPS_H